US674227A - Sensitized paper for photographic printing. - Google Patents

Description

@ UNITED STATES PATENT OFFICE,-

REDEIELD B. WEST, OF GUILFORD, CONNECTICUT SE NSITIZED'PAPER 'FOR PHOTOGRAPHIC PRINTING.,

SPECIFICATION forming part of Letters Patent No. 674,227, dated May 14., 1901.

' Application filed February 26, 1901. Serial No. 48,955. (No specimens.)

To all whom it may concern Be it known that I, REDFIELD B. WEST, of Guilford, in the county of New Havenand State of Connecticut, have invented a new Sensitized Paper for Photographic Printing; and I do hereby declare the following to be a full, clear, and exact description'of the same. This invention relates to an improvement in sensitized paper forphotographic printing, and particularly to paper. in which the print is fixed after exposure by a'bath of water, the object being to produce prints closely resembling in colorthe prints produced by the use of platinum; and it consists in paper sensitized with a compound, as hereinafter described, and particularly recited in the claim.

The sensitizing compound consists of 1ner curous nitrate,eight parts; ferriclactate,eight parts; water, one hundred parts. These parts are united, and paper of suitable quality is coated with the compound, and When thus coated and placed under a negative or drawing to be copied and exposed for a sufficient time to light shows a print of a light-brown color, The print thus made is immersed in water, in which it should be allowed to remain until all of the salts which have not been acted upon by the light are removed from the paper, which is then removed from the bath and allowed to dry. As before stated, these prints closely resemble in color and appearance prints produced with the use of platinum.

The advantages possessed by making prints with my improved paper over that in which platinum is employed are a great reduction 5 in the cost of preparation and the avoidance of all chemical solutions in baths commonly i used for developing, fixing, and clearing such prints. The ferric lactate is particularly adapted, for use with mercurous nitrate in this composition for the reason that no precipitation occurs when the solution of the two salts is made.

Other ferric salts, as a rule,-

give insoluble precipitates with solutions of I mercurous salts. I

The proportions given in the formula may be varied to a certain extent. without materially afiecting the result, I do not, therefore, wish to be understood as limiting the invention'to the exact proportions named; but, Having fully described my invention, what I'claimas new, and desire to secure by Letters Patent, is t l g A sensitized paper for photographic printing, consisting of a paper coated with a solution of mercurous nitrate, ferric lactate and water, inthe proportions substantially as described.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

REDFIELD B. WEST.

:Witnesses:

FRED. C. EARLE, LILLIAN D. KELSEY.